meson: remove the subproject-based library checking

this is not idiomatic, and should not be done (and it did not even
work in the first place); meson is capable of building both
libraries via library() and then you can choose on commandline

it defaults to only shared, but we want both out of box, so specify
that

meson.build

@@ -2,7 +2,7 @@ project(
   'libucontext',
   'c',
   meson_version : '>=0.55.0',
-  default_options: ['c_std=gnu99'],
+  default_options: ['c_std=gnu99', 'default_library=both'],
   version : run_command('head', files('VERSION')).stdout()
 )
 
@@ -52,8 +52,7 @@ project_includes = [
 ]
 
 build_args = [
-  '-D_BSD_SOURCE',
-  '-DPIC'
+  '-D_BSD_SOURCE'
 ]
 
 
@@ -85,39 +84,31 @@ endif
 # ======
 
 headers = include_directories(project_includes)
-is_subproject = meson.is_subproject()
-# Build only static library if subproject
 
-libucontext_target = both_libraries(
+libucontext_target = library(
   'ucontext',
   project_source_files,
   version: meson.project_version(),
-  install : not is_subproject,
+  install : not meson.is_subproject(),
   c_args : build_args,
   pic: true,
   include_directories : headers,
 )
-if is_subproject
-  libucontext_target = libucontext_target.get_static_lib()
-endif
 libucontext_dep = declare_dependency(
   include_directories: headers,
   link_with : libucontext_target
 )
 
 if build_posix
-  libucontext_posix_target = both_libraries(
+  libucontext_posix_target = library(
     'ucontext_posix',
     project_source_files + ['libucontext_posix.c'],
     version: meson.project_version(),
-    install : not is_subproject,
+    install : not meson.is_subproject(),
     c_args : build_args,
     pic: true,
     include_directories : headers,
   )
-  if is_subproject
-    libucontext_posix_target = libucontext_posix_target.get_static_lib()
-  endif
   libucontext_posix_dep = declare_dependency(
     include_directories: headers,
     link_with : libucontext_posix_target
@@ -128,7 +119,7 @@ endif
 # Project
 # =======
 
-if not is_subproject
+if not meson.is_subproject()
   # Make this library usable from the system's
   # package manager.
   install_headers(project_headers, subdir : meson.project_name())
@@ -148,7 +139,7 @@ endif
 # ====
 
 # TODO: meson.build for docs
-if not is_subproject
+if not meson.is_subproject()
   #subdir('docs')
 endif
 
@@ -156,7 +147,6 @@ endif
 # Unit Tests
 # ==========
 
-if not is_subproject
 test('test_libucontext',
   executable(
     'test_libucontext',
@@ -175,4 +165,3 @@ if not is_subproject
     )
   )
 endif
-endif